To factor you have to do this:

s^2 + 9s = -20
+ 20 +20

s^2 + 9s + 20 = 0

now you need to numbers that multiplied give you 20
and then those same 2 numbers have to add to 9

5 x 4 = 20
5+ 4 = 9

(x + 4) (x+ 5)

that means that x= -4, and -5

8 0

3 years ago

The radius of a semicircle is 3 kilometres. What is the semicircle's perimeter?

alina1380 [7]

Answer:

In terms of Pi: $3\pi + 6$ km

Exact value (rounded): 15.42477 km

Approximated (3.14): 15.42 km

Step-by-step explanation:

Hello!

A semicircle's perimeter can be found using the formula: $P = \pi r + 2r$

We can plug in the values to solve for the perimeter.

<h3>Solve</h3>

$P = \pi r + 2r$
$P = \pi(3)+ 2(3)$
$P = 3\pi + 6$

In terms of Pi, it is $3\pi + 6$ ,

Exact value of Pi, it is 15.42477

Approximation of Pi (3.14), it is = 15.42

6 0

2 years ago

Jackie has 1 6/12 pitchers of fruit juice. She and her friend drink 4/12 of a pitcher. How much fruit does Jackie have left?

goldfiish [28.3K]

Answer:

$1\frac{1}{6}\ pitchers\ of\ fruit\ juice$

Step-by-step explanation:

we know that

To find out how much fruit Jackie has left, subtract 4/12 from 1 6/12.

Convert mixed number to an improper fraction first

$1\frac{6}{12}=\frac{1*12+6}{12}=\frac{18}{12}\ pitchers\ of\ fruit\ juice$

$\frac{18}{12}-\frac{4}{12}=\frac{14}{12}\ pitchers\ of\ fruit\ juice$

convert to mixed number

$\frac{14}{12}=\frac{12}{12}+\frac{2}{12}=1\frac{1}{6}\ pitchers\ of\ fruit\ juice$

6 0

3 years ago